Long term evolution (LTE) may be a standard for wireless data communication technology that delivers a high data rate, low latency and packet optimized radio access technology. LTE, however, supports only a packet switched (PS) service while a universal mobile telecommunications system radio access network (UTRAN) supports both of a circuit switched (CS) service and a packet switched (PS) service. In order to provide a CS service in a LTE network, circuit switched (CS) fallback may be employed in the LTE network.
The CS fallback may enable the provisioning of voice and other CS services by reuse of a GSM/EDGE radio access network (GERAN) or a UTRAN CS infrastructure when user equipment is served by a LTE network. GSM may by an abbreviation of a global system for mobile communications and EDGE may be abbreviation of enhanced data rates for GSM evolution. The CS fallback is generally only available if LTE service coverage is overlapped with service coverage of a GERAN or a UTRAN CS network. For example, in the LTE network, a CS fallback procedure may hand over user equipment from a serving LTE cell to an associated non-LTE cell in order to process a mobile originated (MO) call or a mobile terminated (MT) call while the user equipment is camping on the serving LTE cell. The non-LTE cell may be a GERAN cell or a UTRAN cell. The LTE cell may be mapped to a corresponding non-LTE cell with a one to one relationship. A CS fallback call may be transferred from the serving LTE cell to the corresponding non-LTE cell in the CS fallback procedure.
Typically, a cell size of a LTE cell is much greater than that of a UTRAN cell. Accordingly, one LTE cell may be overlaid on multiple UTRAN cells. In such a heterogeneous network environment, user equipment may be redirected from such a LTE cell to a UTRAN cell when the user equipment continuously has a poor reception signal quality for a predetermined duration or when the user equipment needs to perform a CS fallback procedure. In this case, it may be required to provide system information of UTRAN cells that are spatially associated with the serving LTE cell or that are adjacent to a location of user equipment. Typically, a serving LTE cell provides system information of UTRAN cells without consideration of the location of the serving LTE cell or the location of the user equipment. Accordingly, radio resources may be wasted for providing unnecessary system information and related signal processes may be delayed for processing unnecessary system information.